Jelle Vehof, Ph.D., from King's College London, and colleagues conducted a cross-sectional study involving 1,622 female twin volunteers, aged 20 to 83 years, to explore whether pain sensitivity plays a role in patients' experience of DED symptoms. The Ocular Surface Disease Index (OSDI) questionnaire was completed by a subset of 689 women. Quantitative sensory testing was used to assess pain sensitivity and pain tolerance.

The researchers found that 27 percent of the participants were categorized as having DED. Compared to those without DED, women with DED showed a significantly lower heat pain threshold (HPT) and heat pain suprathreshold (HPST). The presence of pain symptoms on the OSDI correlated significantly with the HPT and HPST. DED pain symptoms were almost twice as common for participants with an HPT below the median versus those with an HPT above the median.

"High pain sensitivity and low pain tolerance are associated with symptoms of DED, adding to previous associations of the severity of tear insufficiency, cell damage, and psychological factors," the authors write. "Management of DED symptoms is complex, and physicians need to consider the holistic picture, rather than simply treating ocular signs."